The present invention relates to package security, and more particularly to the art of coating objects to provide an indication as to whether the object has been tampered with. In recent years, and with the expansion of knowledge of methods of analysis, alteration of packages and objects has become more and more difficult to detect. The problem presented by an inability to detect alteration of packages which contain important documents or objects or documents of a classified nature is obvious. It is vital that the recipient of the documents or object be certain that such objects or documents have not been tampered with subsequent to their leaving the originator.
Over the years a number of techniques of increasing complexity have been developed to combat methods of tampering with packages and envelopes. One such technique utilizes dyes or other materials inclosed in an encasement which covers the object, the dyes or material changing colors on exposure to the air. This change of color provides a visual indication that packages or documents have been tampered with to the extent that the encasement has been damaged sufficiently to expose the dye.
Other techniques shown by the prior art include the use of wax seals or strings affixed to packages in a rigid manner, such seals and/or strings being ruptured if the package is tampered with. Increasing sophistication in the art of tampering has proven many of these techniques to be currently unreliable. Wax seals and strings, of course, may easily be replaced so as to give an appearance that the package has never been tampered with. It is also possible to duplicate encasements containing dye or the like, after they have once been tampered with and subsequently removed from the package. Additionally, the encasement type of protection often proves to be too bulky, too time consuming, and too expensive to implement on a large scale.
The present invention solves these problems of the prior art by providing a method by which an object is coated with a material containing some type of inconsistency. When a hologram is subsequently made of the coated object, it is possible to identify a spacial relationship between the coating and the object to a very close tolerance, a tolerance that cannot be duplicated with present day techniques.